Overwinter Survival of Colletotrichum acutatum in Infected Strawberry Fruit in Ohio. L. L. Wilson, Research Assistant II, Department of Plant Pathology, The Ohio State University, Ohio Agricultural Research and Development Center, Wooster 44691. L. V. Madden, and M. A. Ellis. Professors, Department of Plant Pathology, The Ohio State University, Ohio Agricultural Research and Development Center, Wooster 44691. Plant Dis. 76:948-950. Accepted for publication 22 April 1992. Copyright 1992 The American Phytopathological Society. DOI: 10.1094/PD-76-0948.

Colletotrichum acutatum, a causal organism for anthracnose fruit rot of strawberry, was recovered from 100% of all infected strawberry fruit exposed for 18 wk in the laboratory to constant temperatures of –12 and –30 C or six cycles of fluctuating temperatures of –12 or –30 C for 2 wk followed by 5 C for 1 wk. In a 2-yr field study (1988-89, 1989-90), C. acutatum was recovered from nearly 100% of fruit located on the soil surface or 5–8 cm below the soil surface after exposure to winter conditions for 3 mo (November through January), but recovery of C. acutatum decreased with time after 3 mo. After 6 mo of exposure, from November through May over a 3-yr period, the percentage recovery of C. acutatum from nonmummified fruit located on and below the soil surface, respectively, was: 1988-89, 80 and 67%; 1989-90, 60 and 0%; and 1990-91, 7 and 7%. Percentage recovery of C. acutatum was: 1989-90, 53 and 7%, and 1990-91, 47 and 40% from mummified fruit located above and below ground, respectively. This is the first report of C. acutatum overwintering in a northern strawberry production region.